Imaging device

ABSTRACT

An imaging device including: a photoelectric converter; a protection member provided on a light incidence side of the photoelectric converter; a substrate opposed to the protection member with the photoelectric converter interposed therebetween and having a first surface on the photoelectric converter side and a second surface opposed to the first surface; a rewiring layer provided in a selective region of the second surface of the substrate; and a protective resin layer provided on the second surface of the substrate, the second surface of the substrate having an external terminal coupling region exposed from the protective resin layer, and a stress relaxation region exposed from the protective resin layer and disposed at a position different from the external terminal coupling region.

TECHNICAL FIELD

The present disclosure relates to an imaging device suitable for a WCSP(Wafer level Chip Size Package) and the like, for example.

BACKGROUND ART

In recent years, an imaging device such as a WCSP has been developed(for example, see PTL 1). This imaging device includes, for example, aprotection member that covers a photoelectric converter such as aphotodiode (Photo Diode), and a substrate that is opposed to theprotection member with the photoelectric converter interposedtherebetween.

One surface (a surface opposite to a surface on the photoelectricconverter side) of the substrate is provided with a rewiring layer and aterminal for external coupling. The rewiring layer is covered with aprotective resin layer.

CITATION LIST Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No.2012-191055

SUMMARY OF THE INVENTION

In such an imaging device, it is desired to suppress deformation of asubstrate.

It is therefore desirable to provide an imaging device that is able tosuppress deformation of a substrate.

An imaging device according to an embodiment of the present disclosureincludes: a photoelectric converter; a protection member provided on alight incidence side of the photoelectric converter; a substrate opposedto the protection member with the photoelectric converter interposedtherebetween and having a first surface on the photoelectric converterside and a second surface opposed to the first surface; a rewiring layerprovided in a selective region of the second surface of the substrate;and a protective resin layer provided on the second surface of thesubstrate, the second surface of the substrate having an externalterminal coupling region exposed from the protective resin layer, and astress relaxation region exposed from the protective resin layer anddisposed at a position different from the external terminal couplingregion.

In the imaging device according to the embodiment of the presentdisclosure, the second surface of the substrate has the stressrelaxation region exposed from the protective resin layer, which reducesstress applied to the substrate due to the protective resin layer.

According to the imaging device according to the embodiment of thepresent disclosure, the second surface of the substrate has the stressrelaxation region exposed from the protective resin layer, which makesit possible to reduce stress applied to the substrate. This consequentlymakes it possible to suppress deformation of the substrate.

It is to be noted that the above-described contents are mere examples ofthe present disclosure. The effects of the present disclosure are notlimited to the description above, and the effects of the presentdisclosure may be other effects, or may further include other effects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating an example of a functionalconfiguration of an imaging device according to an embodiment of thepresent disclosure.

FIG. 2 is a schematic view of a cross-sectional configuration of a mainpart of the imaging device illustrated in FIG. 1.

FIG. 3 is a schematic plan view of an example of configurations of arewiring layer and a solder ball illustrated in FIG. 2.

FIG. 4 is a schematic plan view of a configuration of a protective resinlayer illustrated in FIG. 2 together with the rewiring layer and thesolder ball.

FIG. 5 is a schematic view of a cross section taken along a line V-Villustrated in FIG. 4.

FIG. 6A is a schematic plan view of a configuration of a main part of animaging device according to a comparative example.

FIG. 6B is a schematic view of a cross-sectional configuration takenalong a line B-B′ illustrated in FIG. 6A.

FIG. 7 is a schematic cross-sectional view for describing an issue ofthe imaging device illustrated in FIG. 6A.

FIG. 8A is a schematic plan view of a configuration of a main part of animaging device according to a modification example 1.

FIG. 8B is a schematic view of a cross-sectional configuration takenalong a line B-B′ illustrated in FIG. 8A.

FIG. 9A is a schematic plan view of a configuration of a main part of animaging device according to a modification example 2.

FIG. 9B is a schematic view of a cross-sectional configuration takenalong a line B-B′ illustrated in FIG. 9A.

FIG. 10 is a schematic plan view of another example (1) of aconfiguration of a protective resin layer illustrated in FIG. 9Atogether with a rewiring layer and a solder ball.

FIG. 11 is a schematic plan view of another example (2) of theconfiguration of the protective resin layer illustrated in FIG. 9Atogether with the rewiring layer and the solder ball.

FIG. 12 is a schematic plan view of a configuration of a main part of animaging device according to a modification example 3.

FIG. 13A is a schematic view of a cross-sectional configuration takenalong a line A-A′ illustrated in FIG. 12.

FIG. 13B is a schematic view of a cross-sectional configuration takenalong a line B-B′ illustrated in FIG. 12.

FIG. 14 is a schematic cross-sectional view of a configuration of a mainpart of an imaging device according to a modification example 4.

FIG. 15 is a schematic cross-sectional view of a configuration of a mainpart of an imaging device according to a modification example 5.

FIG. 16 is a functional block diagram illustrating an example of anelectronic apparatus including the imaging device illustrated in FIG. 1or the like.

FIG. 17 is a block diagram depicting an example of a schematicconfiguration of an in-vivo information acquisition system.

FIG. 18 is a view depicting an example of a schematic configuration ofan endoscopic surgery system.

FIG. 19 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

FIG. 20 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 21 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

MODES FOR CARRYING OUT THE INVENTION

In the following, some embodiments of the present disclosure aredescribed in detail with reference to drawings. It is to be noted thatdescription is given in the following order.

1. Embodiment (an imaging device having a stress relaxation region in asecond surface of a substrate)2. Modification Example 1 (an example in which a narrow pitch regionalso has the stress relaxation region)3. Modification Example 2 (an example in which a protective resin layeris provided to surround a solder ball)4. Modification Example 3 (an example in which the stress relaxationregion is provided at a position not overlapping a rewiring layer)5. Modification Example 4 (an example including one chip)6. Modification Example 5 (an example including three chips)7. Application Example (an electronic apparatus)

8. Practical Application Examples 1. Embodiment (FunctionalConfiguration of Imaging Device 1)

FIG. 1 schematically illustrates an example of a functionalconfiguration of an imaging device (an imaging device 1) according to anembodiment of the present disclosure. The imaging device 1 includes apixel section 200P and a circuit section 200C for driving the pixelsection 200P. The pixel section 200P includes a plurality of lightreception unit regions (pixels P) that are two-dimensionally arranged.The circuit section 200C includes, for example, a row scanner 201, ahorizontal selector 203, a column scanner 204, and a system controller202.

For example, a pixel drive line Lread (for example, a row selection lineand a reset control line) is wired with each pixel row, and a verticalsignal line Lsig is wired with each pixel column. The pixel drive lineLread transmits a drive signal for signal reading from the pixel section200P. One end of the pixel drive line Lread is coupled to an outputterminal, corresponding to each row, of the row scanner 201. The pixelsection 200P includes, for example, a pixel circuit provided for each ofthe pixels P.

The row scanner 201 is a pixel driver that includes a shift register, anaddress decoder, and the like, and drives each of the pixels P of thepixel section 200P, for example, on a row-by-row basis. A signaloutputted from each of the pixels P of a pixel row selected and scannedby the row scanner 201 is supplied to the horizontal selector 203through each of the vertical signal lines Lsig. The horizontal selector203 includes an amplifier, a horizontal selection switch, and the likethat are provided for each of the vertical signal lines Lsig.

The column scanner 204 includes a shift register, an address decoder,and the like, and sequentially drives respective horizontal selectionswitches of the horizontal selector 203 while scanning the horizontalselection switches. Through such selective scanning by the columnscanner 204, signals of respective pixels P transmitted through therespective vertical signal lines Lsig are sequentially outputted to ahorizontal signal line 205, and are inputted to an unillustrated signalprocessor or the like through the horizontal signal line 205.

The system controller 202 receives a clock given from the outside, datainstructing an operation mode, and the like, and outputs data such asinternal information of the imaging device 1. The system controller 202further includes a timing generator that generates various timingsignals, and performs drive control of the row scanner 201, thehorizontal selector 203, the column scanner 204, and the like on thebasis of the various timing signals generated by the timing generator.

(Main Part Configuration of Imaging Device 1)

FIG. 2 is a schematic cross-sectional view of a configuration of a mainpart of the imaging device 1. A specific configuration of the imagingdevice 1 is described with use of FIG. 2.

The imaging device 1 is a WCSP, and includes, for example, a logic chip10 (a second chip), a sensor chip 20 (a first chip), and a protectionmember 40 in this order. A planarization film 31, a color filter 32, anon-chip lens 33, and a sealing resin 34 are provided in this order fromthe sensor chip 20 side between the sensor chip 20 and the protectionmember 40. The imaging device 1 is configured to mount the logic chip 10side onto a printed board such as a mother board, and includes aninsulating film 51, a rewiring layer 52, a solder ball 53, and aprotective resin layer 54 on the logic chip 10 side.

The logic chip 10 includes, for example, a semiconductor substrate 11and a multilayer wiring layer 12, and has a stacked configuration ofthese components. The logic chip 10 includes, for example, a logiccircuit and a control circuit. The entirety of the circuit section 200C(FIG. 1) may be provided in the logic chip 10. Alternatively, a portionof the circuit section 200C may be provided in the sensor chip 20, andthe remaining portion of the circuit section 200C may be provided in thelogic chip 10.

The semiconductor substrate 11 is opposed to the protection member 40with the multilayer wiring layer 12 and the sensor chip 20 interposedtherebetween. The semiconductor substrate 11 has a first surface S11A onthe sensor chip 20 side and a second surface S11B opposed to the firstsurface S11A. The multilayer wiring layer 12 is provided on the firstsurface S11A of the semiconductor substrate 11, and the insulating film51 is provided on the second surface S11B of the semiconductor substrate11. The semiconductor substrate 11 includes, for example, a silicon (Si)substrate. Here, the semiconductor substrate 11 corresponds to aspecific example of a “substrate” in the present disclosure.

The multilayer wiring layer 12 is provided between the semiconductorsubstrate 11 and the sensor chip 20. The multilayer wiring layer 12includes a plurality of wiring lines 121 and an interlayer insulatingfilm 122 that separates the plurality of wiring lines 121. The wiringlines 121 include, for example, copper (Cu), aluminum (Al), tungsten(W), or the like. The interlayer insulating film 122 includes, forexample, a silicon oxide film (SiO), a silicon nitride film (SiN), orthe like.

A through hole 11V is provided at a predetermined position of thesemiconductor substrate 11. The through hole 11V penetrates from thesecond surface S11B to the first surface S11A of the semiconductorsubstrate 11, and reaches the wiring line 121 of the multilayer wiringlayer 12 or a pad electrode.

The insulating film 51 covers a side wall of the through hole 11V fromthe second surface S11B of the semiconductor substrate 11. Theinsulating film 51 includes, for example, a silicon oxide film (SiO), asilicon nitride film (SiN), or the like.

The rewiring layer 52 covers the side wall of the through hole 11V withthe insulating film 51 interposed therebetween, and covers a bottomsurface of the through hole 11V. On the bottom surface of the throughhole 11V, the rewiring layer 52 is in contact with the wiring line 121of the multilayer wiring layer 12 or the pad electrode. The rewiringlayer 52 extends from the through hole 11V to the second surface S11B ofthe semiconductor substrate 11, and is drawn to a formation region ofthe solder ball 53. On the second surface S11B of the semiconductorsubstrate 11, the rewiring layer 52 is disposed in a selective region ofthe second surface S11B with the insulating film 51 interposedtherebetween. The rewiring layer 52 includes, for example, copper (Cu),tungsten (W), titanium (Ti), tantalum (Ta), a titanium tungsten alloy(TiW), a polysilicon, or the like.

FIG. 3 illustrates an example of a planar configuration of the rewiringlayer 52 together with the solder ball 53. A plurality of rewiringlayers 52 extending in directions substantially parallel to each other(a Y direction in FIG. 3) is provided on the second surface S11B of thesemiconductor substrate 11. The second surface S11B of the semiconductorsubstrate 11 has, for example, a narrow pitch region 52N and a widepitch region 52W. In the narrow pitch region 52N, the rewiring layers 52adjacent to each other are disposed at a predetermined interval (a pitchP_(n)). In the wide pitch region 52W, the rewiring layers 52 adjacent toeach other are disposed at an interval (a pitch P_(w)) wider than thepitch P_(n) in the narrow pitch region 52N. A width (a size in an Xdirection in FIG. 3) of the rewiring layer 52 is, for example, 20 μm to40 μm, the pitch P_(n) is 20 μm to 40 μm, and the pitch P_(w) is 100 μmto 200 μm.

The solder ball 53 is coupled to the rewiring layer 52 drawn onto thesecond surface S11B of the semiconductor substrate 11 (FIG. 2). Thesolder ball 53 functions as an external coupling terminal for mountingonto a printed board, and includes, for example, a high melting pointlead-free solder such as Sn—Ag—Cu, or the like. For example, a pluralityof solder balls 53 is provided on the second surface S11B of thesemiconductor substrate 11 to be regularly arranged at a predeterminedpitch. The arrangement of the solder balls 53 is appropriately set inaccordance with a position of a bonding pad on a mounted printed board(not illustrated) side. The solder ball 53 is electrically coupled tothe wiring line 121 of the multilayer wiring layer 12 or the padelectrode via the rewiring layer 52. Here, the solder ball 53corresponds to a specific example of an “external terminal” in thepresent disclosure.

The protective resin layer 54 provided on the second surface S11B of thesemiconductor substrate 11 protects the rewiring layer 52. Theprotective resin layer 54 is not provided in a region in which thesolder ball 53 is provided of the second surface S11B of thesemiconductor substrate 11. That is, the solder ball 53 is coupled to aportion, exposed from the protective resin layer 54, of the rewiringlayer 52. In other words, the second surface S11B of the semiconductorsubstrate 11 has an external terminal coupling region 54A that causesthe rewiring layer 52 to be exposed from the protective resin layer 54,and the solder ball 53 is coupled to the rewiring layer 52 in theexternal terminal coupling region 54A. The protective resin layer 54includes, for example, a solder resist, and includes an epoxy-based,polyimide-based, silicon-based, or acrylic-based resin, and the like.

In the present embodiment, the second surface S11B of the semiconductorsubstrate 11 has a stress relaxation region 54B in addition to theexternal terminal coupling region 54A. The stress relaxation region 54Bis a region, exposed from the protective resin layer 54, of the secondsurface S11B of the semiconductor substrate 11, and is disposed at aposition not overlapping the external terminal coupling region 54A inplan (an XY plane in FIG. 2) view. In the stress relaxation region 54B,for example, the protective resin layer 54 is not provided, and therewiring layer 52 or the insulating film 51 is exposed. As described indetail later, providing such a stress relaxation region 54B in thesecond surface S11B of the semiconductor substrate 11 makes it possibleto reduce stress applied to the semiconductor substrate 11.

FIGS. 4 and 5 illustrate an example of the position of the stressrelaxation region 54B. FIG. 4 illustrates an example of planarconfigurations of the rewiring layer 52, the solder ball 53, and theprotective resin layer 54, and FIG. 5 illustrates a cross-sectionalconfiguration taken along a line V-V illustrated in FIG. 4. Asillustrated, the protective resin layer 54 may be provided at a positionoverlapping the narrow pitch region 52N in plan view, and the stressrelaxation region 54B may be disposed at a position overlapping the widepitch region 52W. In the narrow pitch region 52N, migration (corrosion)easily occurs due to the rewiring layer 52. Selectively providing theprotective resin layer 54 in the narrow pitch region 52N makes itpossible to suppress occurrence of migration.

The sensor chip 20 provided between the logic chip 10 and the protectionmember 40 includes, for example, a multilayer wiring layer 22 and asemiconductor substrate 21 in this order from the logic chip 10 side.

The multilayer wiring layer 22 of the sensor chip 20 is in contact withthe multiplayer wiring layer 12 of the logic chip 10, and a bondedsurface S between the sensor chip 20 and the logic chip 10 is providedbetween the multilayer wiring layer 22 and the multilayer wiring layer12. The multilayer wiring layer 22 includes a plurality of wiring lines221 and an interlayer insulating film 222 that separates the pluralityof wiring lines 221. The plurality of wiring lines 221 is included in apixel circuit of the pixel section 200P (FIG. 1). The wiring lines 221include, for example, copper (Cu), aluminum (Al), tungsten (W), or thelike. The interlayer insulating film 222 includes, for example, asilicon oxide film (SiO), a silicon nitride film (SiN), or the like.

The semiconductor substrate 21 provided between the multilayer wiringlayer 22 and the planarization film 31 includes, for example, a silicon(Si) substrate. A photodiode (PD) 211 is provided for each of the pixelsP in the semiconductor substrate 21 of the sensor chip 20. The PD 211 isprovided in proximity to a light reception surface (a surface oppositeto a surface on the multilayer wiring layer 22 side) of thesemiconductor substrate 21. Here, the PD 211 corresponds to a specificexample of a “photoelectric converter” in the present disclosure.

Through electrodes 223 a and 223 b are provided in the sensor chip 20.The through electrodes 223 a and 223 b are coupled to each other via acoupling wiring line 224 provided between the semiconductor substrate 21and the planarization film 31. The coupling wiring line 224 is disposedat a position not overlapping the PD 211 in plan view. The throughelectrode 223 a penetrates through the semiconductor substrate 21 andthe multilayer wiring layer 22 to be coupled to the wiring line 121 ofthe logic chip 10. The through electrode 223 b penetrates through thesemiconductor substrate 11 to be coupled to the wiring line 221 of thesensor chip 20. That is, the multilayer wiring layer 22 of the sensorchip 20 is electrically coupled to the multilayer wiring layer 12 of thelogic chip 10 via the through electrodes 223 a and 223 b and thecoupling wiring line 224. An insulating film 225 is provided betweeneach of the through electrodes 223 a and 223 b and the semiconductorsubstrate 21.

The planarization film 31 provided between the semiconductor substrate21 and the color filter 32 planarizes the light reception surface of thesemiconductor substrate 21. The planarization film 31 includes, forexample, silicon oxide (SiO) and the like.

The color filter 32 provided on the light reception surface of thesensor chip 20 is, for example, one of a red (R) filter, a green (G)filter, a blue (B) filter, and a white filter (W), and is provided foreach of the pixels P, for example. These color filters 32 are providedin a regular color arrangement (for example, a Bayer arrangement).Providing such color filters 32 allows the imaging device 1 to acquirecolor light reception data corresponding to the color arrangement.

The on-chip lens 33 on the color filter 32 is provided for each of thepixels P at a position opposed to the PD 211 of the sensor chip 20.Light having entered the on-chip lens 33 is concentrated on the PD 211in each of the pixels P. A lens system of the on-chip lens 33 is set ata value corresponding to a size of the pixel P. Examples of lensmaterials of the on-chip lens 33 include an organic material, a siliconoxide film (SiO), and the like.

The protection member 40 covering the sensor chip 20 with the on-chiplens 33 interposed therebetween has a thickness that is sufficientlylarger than thicknesses of the logic chip 10 and the sensor chip 20. Theprotection member 40 includes, for example, a glass substrate. Forexample, an IR (infrared) cut filter or the like may be provided on asurface (a surface opposite to a surface on the sensor chip 20 side) ofthe protection member 40 provided on a light incidence side of thesensor chip 20. The protection member 40 is opposed to the logic chip 10with the sensor chip 20 interposed therebetween.

The sealing resin 34 provided between the protection member 40 and theon-chip lens 33 has, for example, a refractive index substantially equalto a refractive index of the protection member 40. The sealing resin 34is provided to fill a space between the protection member 40 and thesensor chip 20. The protection member 40 and the sensor chip 20 areadhered to each other at edges thereof. The imaging device 1 may have acavity structure having an airtight space between the protection member40 and the sensor chip 20.

(Workings and Effects of Imaging Device 1)

In the imaging device 1, the wiring line 121 or the pad electrodeprovided in the multilayer wiring layer 12 of the logic chip 10 is drawnto the second surface S11B of the semiconductor substrate 11 by therewiring layer 52 provided in the through hole 11 v. This causesinputting and outputting of signals between the outside from the secondsurface S11B side of the semiconductor substrate 11 and the sensor chip20. In such an imaging device 1, an opening section for pad electrodecoupling on the light reception surface side of the sensor chip 20 isnot necessary, which makes it possible to reduce a chip size.

In addition, in the imaging device 1, the sensor chip 20 and the logicchip 10 are stacked, which makes it possible to reduce the size of theimaging device 1, as compared with a case where the pixel section 200Pand the circuit section 200C are provided in one semiconductorsubstrate.

In particular, in the imaging device 1 according to the presentembodiment, the second surface S11B of the semiconductor substrate 11has the stress relaxation region 54B exposed from the protective resinlayer 54, which reduces stress applied to the semiconductor substrate 11due to the protective resin layer 54. This makes it possible to suppressdeformation of the semiconductor substrate 11. The workings and theeffects are described below with use of a comparative example.

FIGS. 6A and 6B schematically illustrate a configuration of a main partof an imaging device (an imaging device 100) according to a comparativeexample. FIG. 6A illustrates a planar configuration on the secondsurface S11B side of the semiconductor substrate 11, and FIG. 6Billustrates a cross-sectional configuration taken along a line B-B′illustrated in FIG. 6A. The imaging device 100 includes the rewiringlayer 52, the solder ball 53, and the protective resin layer 54 on thesecond surface S11B of the semiconductor substrate 11, as with theimaging device 1.

In the imaging device 100, of the second surface S11B of thesemiconductor substrate 11, only a region provided with the solder ball53 is exposed from the protective resin layer 54, and a region otherthan the region is covered with the protective resin layer 54. In otherwords, in the imaging device 100, the second surface S11B of thesemiconductor substrate 11 has only the external terminal couplingregion 54A, and does not have a stress relaxation region (the stressrelaxation region 54B in FIG. 2).

In such an imaging device 100, for example, during a manufacturingprocess, there is a possibility that the semiconductor substrate 11 isgreatly warped, as illustrated in FIG. 7. This is caused by applicationof stress to the semiconductor substrate 11 due to a difference betweenthe thermal expansion coefficient of the protective resin layer 54 andthe thermal expansion coefficient of the semiconductor substrate 11. Thelarger the area of the protective resin layer 54 provided on the secondsurface S11B of the semiconductor substrate 11 is, the larger the stressapplied to the semiconductor substrate 11 becomes. Accordingly, in theimaging device 100 in which the protective resin layer 54 is provided onthe substantially entire second surface S11B of the semiconductorsubstrate 11, large stress is applied to the semiconductor substrate 11due to the protective resin layer 54. In a case where the semiconductorsubstrate 11 is deformed, handling in the manufacturing process becomesdifficult. In addition, there is a possibility that reliability isreduced.

In contrast, in the imaging device 1 according to the presentembodiment, the second surface S11B of the semiconductor substrate 11has the stress relaxation region 54B in addition to the externalterminal coupling region 54A. In the stress relaxation region 54B, thesecond surface S11B of the semiconductor substrate 11 is exposed fromthe protective resin layer 54. Accordingly, in the imaging device 1, ascompared with the imaging device 100, the area of the protective resinlayer 54 provided on the second surface S11B of the semiconductorsubstrate 11 becomes small, and stress applied to the semiconductorsubstrate 11 due to the protective resin layer 54 is reduced. This makesit possible to suppress deformation of the semiconductor substrate 11.Thus, handling in the manufacturing process becomes easy, and it is alsopossible to suppress reduction in reliability.

As described above, in the imaging device 1 according to the presentembodiment, the second surface S11B of the semiconductor substrate 11has the stress relaxation region 54B exposed from the protective resinlayer 54, which makes it possible to reduce stress applied to thesemiconductor substrate 11. This makes it possible to suppressdeformation of the semiconductor substrate 11.

In addition, for example, the stress relaxation region 54B is disposedat a position overlapping the wide pitch region 52W, and the protectiveresin layer 54 is provided in the narrow pitch region 52N. This makes itpossible to protect the rewiring layers 52 in the narrow pitch region bythe protective resin layer 54 while reducing stress applied to thesemiconductor substrate 11. This consequently makes it possible toreduce deformation of the semiconductor substrate 11 and suppressoccurrence of migration of the rewiring layers 52.

Modification examples of the above-described embodiment are describedbelow, and the same components as those in the above-describedembodiment are denoted by the same reference numerals, and descriptionthereof is omitted as appropriate.

Modification Example 1

FIGS. 8A and 8B illustrate a configuration of a main part of the imagingdevice 1 according to a modification example 1 of the above-describedembodiment. FIG. 8A illustrates planar configurations of thesemiconductor substrate 11 (the second surface S11B), the rewiring layer52, the solder ball 53, and the protective resin layer 54, and FIG. 8Billustrates a cross-sectional configuration taken along a line B-B′illustrated in FIG. 8A. Here, the protective resin layer 54 is providedbetween the rewiring layers 52 adjacent to each other in the narrowpitch region 52N. That is, the stress relaxation region 54B is providedalso at a position overlapping the narrow pitch region 52N in plan view.Except for this point, the imaging device 1 according to themodification example 1 has a configuration similar to that of theimaging device 1 according to the above-described embodiment, and theworkings and effects thereof are also similar.

The protective resin layer 54 has a rectangular planar shape, and isprovided at a position not overlapping the rewiring layer 52 in planview. For example, a plurality of rectangular protective resin layers 54is disposed in stripes on the second surface S11B of the semiconductorsubstrate 11. A width of each of the protective resin layers 54 (a sizein the X direction in FIGS. 8A and 8B) is smaller than the pitch P_(n)of the narrow pitch region 52N, and is, for example, 20 μm to 40 μm.

The stress relaxation region 54B is provided at a position overlappingthe rewiring layer 52 in plan view in the narrow pitch region 52N. Thus,the stress relaxation region 54B may be provided at a positionoverlapping a portion of the narrow pitch region 52N in addition to theposition overlapping the wide pitch region 52W.

Modification Example 2

FIGS. 9A and 9B illustrate a configuration of a main part of the imagingdevice 1 according to a modification example 2 of the above-describedembodiment. FIG. 9A illustrates planar configurations of thesemiconductor substrate 11 (the second surface S11B), the rewiring layer52, the solder ball 53, and the protective resin layer 54, and FIG. 9Billustrates a cross-sectional configuration taken along a line B-B′illustrated in FIG. 9A. Here, the protective resin layer 54 is providedto surround the solder ball 53. Except for this point, the imagingdevice 1 according to the modification example 2 has a configurationsimilar to that of the imaging device 1 according to the above-describedembodiment, and the workings and effects thereof are also similar.

The protective resin layer 54 has an annular planar shape. A pluralityof annular protective resin layers 54 is provided on the second surfaceS11B of the semiconductor substrate 11. Of the second surface S11B ofthe semiconductor substrate 11, a region other than a region in whichthe protective resin layer 54 is provided is the external terminalcoupling region 54A or the stress relaxation region 54B. For example,the external terminal coupling region 54A is provided inside each of theplurality of annular protective resin layers 54, and the stressrelaxation region 54B is provided outside each of the plurality ofannular protective resin layers 54.

Providing the protective resin layer 54 to surround the solder ball 53makes it easy to form the solder ball 53 and the solder ball 53 at aprecise position.

FIGS. 10 and 11 illustrate another example of the configuration of theprotective resin layer 54 illustrated in FIG. 9A.

As illustrated in FIG. 10, the configuration of the protective resinlayer 54 described in the present modification example may be combinedwith the configuration of the protective resin layer 54 described in theabove-described embodiment. Specifically, the protective resin layer 54surrounding the solder ball 53 and the protective resin layer 54 at aposition overlapping the narrow pitch region 52N may be provided on thesecond surface S11B of the semiconductor substrate 11. The stressrelaxation region 54B is provided in a region outside the annularprotective resin layer 54 and at a position overlapping the wide pitchregion 52W.

As illustrated in FIG. 11, the configuration of the protective resinlayer 54 described in the present modification example may be combinedwith the configuration of the protective resin layer 54 described theabove-described modification example 1. Specifically, the protectiveresin layer 54 surrounding the solder ball 53 and the protective resinlayer 54 disposed between the rewiring layers 52 adjacent to each otherin the narrow pitch region 52N may be provided on the second surfaceS11B of the semiconductor substrate 11. The stress relaxation region 54Bis provided in a region outside the annular protective resin layer 54and at a position overlapping the wide pitch region 52W, and in a regionoutside the annular protective resin layer 54 and at a positionoverlapping the rewiring layer 52 in the narrow pitch region 52N.

Modification Example 3

FIG. 12 schematically illustrates a planar configuration of a main partof the imaging device according to a modification example 3 of theabove-described embodiment. Here, the stress relaxation region 54B isprovided at a position not overlapping the rewiring layer 52. Except forthis point, the imaging device 1 according to the modification example 3has a configuration similar to that of the imaging device 1 according tothe above-described embodiment, and the workings and effects thereof arealso similar.

FIG. 13A illustrates a cross-sectional configuration taken along a lineA-A′ illustrated in FIG. 12, and FIG. 13B illustrates a cross-sectionalconfiguration taken along a line B-B′ illustrated in FIG. 12. Forexample, the protective resin layer 54 covers all the rewiring layers52. The stress relaxation region 54B is provided, for example, at aposition not overlapping the rewiring layers 52 in the wide pitch region52W. The stress relaxation region 54B includes, for example, a slit ofthe protective resin layer 54.

The stress relaxation region 54B is provided at the position notoverlapping the rewiring layers 52, thereby causing the protective resinlayer 54 to protect the rewiring layers 52. This makes it possible tosuppress occurrence of migration of the rewiring layers 52.

Modification Example 4

FIG. 14 schematically illustrates a cross-sectional configuration of amain part of the imaging device 1 according to a modification example 4of the above-described embodiment. The imaging device 1 includes onechip (the sensor chip 20). That is, the imaging device 1 does notinclude a logic chip (the logic chip 10 in FIG. 2). Except for thispoint, the imaging device 1 according to the modification example 4 hasa configuration similar to that of the imaging device 1 according to theabove-described embodiment, and the workings and effects thereof arealso similar.

The sensor chip 20 includes, for example, a supporting substrate 23, themultilayer wiring layer 22, and the semiconductor substrate 21 in thisorder. The supporting substrate 23 is opposed to the protection member40 with the multilayer wiring layer 22 and the semiconductor substrate21 interposed therebetween. The supporting substrate 23 has a firstsurface S23A on the semiconductor substrate 21 side and a second surfaceS23B opposed to the first surface S23A. The supporting substrate 23includes, for example, a silicon (Si) substrate. The solder ball 53 andthe like are provided on the second surface S23B of the supportingsubstrate 23. In the imaging device 1, the second surface S23B of thesupporting substrate 23 has the external terminal coupling region 54Aand the stress relaxation region 54B.

Modification Example 5

FIG. 15 schematically illustrates a cross-sectional configuration of amain part of the imaging device 1 according to a modification example 5of the above-described embodiment. The imaging device 1 includes threechips (the logic chip 10, the sensor chip 20, and a memory chip 60). Theimaging device 1 includes, for example, the memory chip 60 (a secondchip), the logic chip 10 (a third chip), the sensor chip 20 (a firstchip), and the protection member 40 in this order. Except for thispoint, the imaging device 1 according to the modification example 5 hasa configuration similar to that of the imaging device 1 according to theabove-described embodiment, and the workings and effects are alsosimilar.

The memory chip 60 includes, for example, a memory circuit. The memorychip 60 is opposed to the protection member 40 with the logic chip 10and the sensor chip 20 interposed therebetween. The memory chip 60includes, for example, a multilayer wiring layer 62 and a semiconductorsubstrate 61 in this order from the logic chip 10 side. Thesemiconductor substrate 61 has a first surface S61A on the sensor chip20 side and a second surface S61B opposed to the first surface S61A. Thesemiconductor substrate 61 includes, for example, a silicon (Si)substrate. The solder ball 53 and the like are provided on the secondsurface S61B of the semiconductor substrate 61. In the imaging device 1,the second surface S61B of the semiconductor substrate 61 has theexternal terminal coupling region 54A and the stress relaxation region54B.

A logic chip including a logic circuit may be provided instead of thememory chip 60. That is, the imaging device 1 may include the sensorchip 20 and two logic chips.

Application Example

The above-described imaging device 1 is applicable, for example, tovarious types of electronic apparatuses such as a camera that is able tocapture an image of light of a wavelength in a visible region. FIG. 16illustrates a schematic configuration of an electronic apparatus 3 (acamera) as an example thereof. The electronic apparatus 3 is, forexample, a camera that is able to shoot a still image or a moving image.The electronic apparatus 3 includes the imaging device 1, an opticalsystem (an optical lens) 310, a shutter device 311, a driver 313 thatdrives the imaging device 1 and the shutter device 311, and a signalprocessor 312.

The optical system 310 guides image light (incident light) from asubject to the imaging device 1. The optical system 310 may include aplurality of optical lenses. The shutter device 311 controls a period inwhich the imaging device 1 is irradiated with light and a period inwhich the light is blocked. The driver 313 controls a transfer operationof the imaging device 1 and a shutter operation of the shutter device311. The signal processor 312 performs various kinds of signalprocessing on a signal outputted from the imaging device 1. An imagesignal Dout having been subjected to the signal processing is stored ina storage medium such as a memory or outputted to a monitor or the like.

<Example of Application to In-Vivo Information Acquisition System>

Further, the technology (present technology) according to the presentdisclosure is applicable to a variety of products. For example, thetechnology according to the present disclosure may be applied to anendoscopic surgery system.

FIG. 17 is a block diagram depicting an example of a schematicconfiguration of an in-vivo information acquisition system of a patientusing a capsule type endoscope, to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

The in-vivo information acquisition system 10001 includes a capsule typeendoscope 10100 and an external controlling apparatus 10200.

The capsule type endoscope 10100 is swallowed by a patient at the timeof inspection. The capsule type endoscope 10100 has an image pickupfunction and a wireless communication function and successively picks upan image of the inside of an organ such as the stomach or an intestine(hereinafter referred to as in-vivo image) at predetermined intervalswhile it moves inside of the organ by peristaltic motion for a period oftime until it is naturally discharged from the patient. Then, thecapsule type endoscope 10100 successively transmits information of thein-vivo image to the external controlling apparatus 10200 outside thebody by wireless transmission.

The external controlling apparatus 10200 integrally controls operationof the in-vivo information acquisition system 10001. Further, theexternal controlling apparatus 10200 receives information of an in-vivoimage transmitted thereto from the capsule type endoscope 10100 andgenerates image data for displaying the in-vivo image on a displayapparatus (not depicted) on the basis of the received information of thein-vivo image.

In the in-vivo information acquisition system 10001, an in-vivo imageimaged a state of the inside of the body of a patient can be acquired atany time in this manner for a period of time until the capsule typeendoscope 10100 is discharged after it is swallowed.

A configuration and functions of the capsule type endoscope 10100 andthe external controlling apparatus 10200 are described in more detailbelow.

The capsule type endoscope 10100 includes a housing 10101 of the capsuletype, in which a light source unit 10111, an image pickup unit 10112, animage processing unit 10113, a wireless communication unit 10114, apower feeding unit 10115, a power supply unit 10116 and a control unit10117 are accommodated.

The light source unit 10111 includes a light source such as, forexample, a light emitting diode (LED) and irradiates light on an imagepickup field-of-view of the image pickup unit 10112.

The image pickup unit 10112 includes an image pickup element and anoptical system including a plurality of lenses provided at a precedingstage to the image pickup element. Reflected light (hereinafter referredto as observation light) of light irradiated on a body tissue which isan observation target is condensed by the optical system and introducedinto the image pickup element. In the image pickup unit 10112, theincident observation light is photoelectrically converted by the imagepickup element, by which an image signal corresponding to theobservation light is generated. The image signal generated by the imagepickup unit 10112 is provided to the image processing unit 10113.

The image processing unit 10113 includes a processor such as a centralprocessing unit (CPU) or a graphics processing unit (GPU) and performsvarious signal processes for an image signal generated by the imagepickup unit 10112. The image processing unit 10113 provides the imagesignal for which the signal processes have been performed thereby as RAWdata to the wireless communication unit 10114.

The wireless communication unit 10114 performs a predetermined processsuch as a modulation process for the image signal for which the signalprocesses have been performed by the image processing unit 10113 andtransmits the resulting image signal to the external controllingapparatus 10200 through an antenna 10114A. Further, the wirelesscommunication unit 10114 receives a control signal relating to drivingcontrol of the capsule type endoscope 10100 from the externalcontrolling apparatus 10200 through the antenna 10114A. The wirelesscommunication unit 10114 provides the control signal received from theexternal controlling apparatus 10200 to the control unit 10117.

The power feeding unit 10115 includes an antenna coil for powerreception, a power regeneration circuit for regenerating electric powerfrom current generated in the antenna coil, a voltage booster circuitand so forth. The power feeding unit 10115 generates electric powerusing the principle of non-contact charging.

The power supply unit 10116 includes a secondary battery and storeselectric power generated by the power feeding unit 10115. In FIG. 17, inorder to avoid complicated illustration, an arrow mark indicative of asupply destination of electric power from the power supply unit 10116and so forth are omitted. However, electric power stored in the powersupply unit 10116 is supplied to and can be used to drive the lightsource unit 10111, the image pickup unit 10112, the image processingunit 10113, the wireless communication unit 10114 and the control unit10117.

The control unit 10117 includes a processor such as a CPU and suitablycontrols driving of the light source unit 10111, the image pickup unit10112, the image processing unit 10113, the wireless communication unit10114 and the power feeding unit 10115 in accordance with a controlsignal transmitted thereto from the external controlling apparatus10200.

The external controlling apparatus 10200 includes a processor such as aCPU or a GPU, a microcomputer, a control board or the like in which aprocessor and a storage element such as a memory are mixedlyincorporated. The external controlling apparatus 10200 transmits acontrol signal to the control unit 10117 of the capsule type endoscope10100 through an antenna 10200A to control operation of the capsule typeendoscope 10100. In the capsule type endoscope 10100, an irradiationcondition of light upon an observation target of the light source unit10111 can be changed, for example, in accordance with a control signalfrom the external controlling apparatus 10200. Further, an image pickupcondition (for example, a frame rate, an exposure value or the like ofthe image pickup unit 10112) can be changed in accordance with a controlsignal from the external controlling apparatus 10200. Further, thesubstance of processing by the image processing unit 10113 or acondition for transmitting an image signal from the wirelesscommunication unit 10114 (for example, a transmission interval, atransmission image number or the like) may be changed in accordance witha control signal from the external controlling apparatus 10200.

Further, the external controlling apparatus 10200 performs various imageprocesses for an image signal transmitted thereto from the capsule typeendoscope 10100 to generate image data for displaying a picked upin-vivo image on the display apparatus. As the image processes, varioussignal processes can be performed such as, for example, a developmentprocess (demosaic process), an image quality improving process(bandwidth enhancement process, a super-resolution process, a noisereduction (NR) process and/or image stabilization process) and/or anenlargement process (electronic zooming process). The externalcontrolling apparatus 10200 controls driving of the display apparatus tocause the display apparatus to display a picked up in-vivo image on thebasis of generated image data. Alternatively, the external controllingapparatus 10200 may also control a recording apparatus (not depicted) torecord generated image data or control a printing apparatus (notdepicted) to output generated image data by printing.

One example of the in-vivo information acquisition system to which thetechnology according to the present disclosure may be applied has beendescribed above. The technology according to the present disclosure maybe applied, for example, to the image pickup unit 10112 among theabove-described components. This increases the detection accuracy.

<Example of Application to Endoscopic Surgery System>

The technology (present technology) according to the present disclosureis applicable to a variety of products. For example, the technologyaccording to the present disclosure may be applied to an endoscopicsurgery system.

FIG. 18 is a view depicting an example of a schematic configuration ofan endoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In FIG. 18, a state is illustrated in which a surgeon (medical doctor)11131 is using an endoscopic surgery system 11000 to perform surgery fora patient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy device 11112,a supporting arm apparatus 11120 which supports the endoscope 11100thereon, and a cart 11200 on which various apparatus for endoscopicsurgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody cavity of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which includes as a rigid endoscope havingthe lens barrel 11101 of the hard type. However, the endoscope 11100 mayotherwise be included as a flexible endoscope having the lens barrel11101 of the flexible type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel 11101by a light guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body cavity of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a forward-viewing endoscope or may be an oblique-viewingendoscope or a side-viewing endoscope.

An optical system and an image pickup element are provided in the insideof the camera head 11102 such that reflected light (observation light)from the observation target is condensed on the image pickup element bythe optical system. The observation light is photo-electricallyconverted by the image pickup element to generate an electric signalcorresponding to the observation light, namely, an image signalcorresponding to an observation image. The image signal is transmittedas RAW data to a CCU 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or a like to change an image pickup condition (typeof irradiation light, magnification, focal distance or the like) by theendoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy device 11112 for cautery or incision of a tissue, sealing of ablood vessel or the like. A pneumoperitoneum apparatus 11206 feeds gasinto a body cavity of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body cavity in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagepickup elements of the camera head 11102 are controlled in synchronismwith the irradiation timings. Then images individually corresponding tothe R, G and B colors can be also picked up time-divisionally. Accordingto this method, a color image can be obtained even if color filters arenot provided for the image pickup element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the image pickup element of the camerahead 11102 in synchronism with the timing of the change of the intensityof light to acquire images time-divisionally and synthesizing theimages, an image of a high dynamic range free from underexposed blockedup shadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrow band in comparison with irradiation lightupon ordinary observation (namely, white light), narrow band observation(narrow band imaging) of imaging a predetermined tissue such as a bloodvessel of a superficial portion of the mucous membrane or the like in ahigh contrast is performed. Alternatively, in special light observation,fluorescent observation for obtaining an image from fluorescent lightgenerated by irradiation of excitation light may be performed. Influorescent observation, it is possible to perform observation offluorescent light from a body tissue by irradiating excitation light onthe body tissue (autofluorescence observation) or to obtain afluorescent light image by locally injecting a reagent such asindocyanine green (ICG) into a body tissue and irradiating excitationlight corresponding to a fluorescent light wavelength of the reagentupon the body tissue. The light source apparatus 11203 can be configuredto supply such narrow-band light and/or excitation light suitable forspecial light observation as described above.

FIG. 19 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 18.

The camera head 11102 includes a lens unit 11401, an image pickup unit11402, a driving unit 11403, a communication unit 11404 and a camerahead controlling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The number of image pickup elements which is included by the imagepickup unit 11402 may be one (single-plate type) or a plural number(multi-plate type). Where the image pickup unit 11402 is configured asthat of the multi-plate type, for example, image signals correspondingto respective R, G and B are generated by the image pickup elements, andthe image signals may be synthesized to obtain a color image. The imagepickup unit 11402 may also be configured so as to have a pair of imagepickup elements for acquiring respective image signals for the right eyeand the left eye ready for three dimensional (3D) display. If 3D displayis performed, then the depth of a living body tissue in a surgicalregion can be comprehended more accurately by the surgeon 11131. It isto be noted that, where the image pickup unit 11402 is configured asthat of stereoscopic type, a plurality of systems of lens units 11401are provided corresponding to the individual image pickup elements.

Further, the image pickup unit 11402 may not necessarily be provided onthe camera head 11102. For example, the image pickup unit 11402 may beprovided immediately behind the objective lens in the inside of the lensbarrel 11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the image pickup unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the image pickup unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to image pickupconditions such as, for example, information that a frame rate of apicked up image is designated, information that an exposure value uponimage picking up is designated and/or information that a magnificationand a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be designated bythe user or may be set automatically by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,an auto exposure (AE) function, an auto focus (AF) function and an autowhite balance (AWB) function are incorporated in the endoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy device11112 is used and so forth by detecting the shape, color and so forth ofedges of objects included in a picked up image. The control unit 11413may cause, when it controls the display apparatus 11202 to display apicked up image, various kinds of surgery supporting information to bedisplayed in an overlapping manner with an image of the surgical regionusing a result of the recognition. Where surgery supporting informationis displayed in an overlapping manner and presented to the surgeon11131, the burden on the surgeon 11131 can be reduced and the surgeon11131 can proceed with the surgery with certainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

One example of the endoscopic surgery system to which the technologyaccording to the present disclosure may be applied has been describedabove. The technology according to the present disclosure may be appliedto the image pickup unit 11402 among the above-described components.Applying the technology according to the present disclosure to the imagepickup unit 11402 increases the detection accuracy.

It is to be noted that the endoscopic surgery system has been describedhere as an example, but the technology according to the presentdisclosure may be additionally applied, for example, to a microscopicsurgery system or the like.

<Example of Application to Mobile Body>

The technology according to the present disclosure is applicable to avariety of products. For example, the technology according to thepresent disclosure may be achieved as a device mounted on any type ofmobile body such as a vehicle, an electric vehicle, a hybrid electricvehicle, a motorcycle, a bicycle, a personal mobility, an airplane, adrone, a vessel, a robot, a construction machine, or an agriculturalmachine (tractor).

FIG. 20 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 20, the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 20, anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 21 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 21, the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 21 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

One example of the vehicle control system to which the technologyaccording to the present disclosure may be applied has been describedabove. The technology according to the present disclosure may be appliedto the imaging section 12031 among the components described above.Applying the technology according to the present disclosure to theimaging section 12031 makes it possible to obtain a shot image that iseasier to see. This makes it possible to decrease the fatigue of adriver.

The present disclosure has been described above with reference to theembodiment and the modification examples; however, the presentdisclosure contents are not limited to the embodiment and the likedescribed above, and may be modified in a variety of ways. For example,the configuration of the imaging device in the embodiment describedabove are merely exemplary, and may further include any other layer. Inaddition, the materials and thicknesses of the respective layers aremerely exemplary as well, and are not limited to those described above.

In addition, in the embodiment and the like described above, descriptionhas been given of examples of the configuration of the stress relaxationregion 54B; however, the configuration of the stress relaxation region54B is not limited to these examples.

In addition, in the embodiment and the like described above, descriptionhas been given of a case where the rewiring layer 52 is provided in thethrough hole 11V of the semiconductor substrate 11 (FIG. 2); however,the through hole 11V may be filled with an electrical conductordifferent from the rewiring layer 52, and the electrical conductor maybe coupled to the rewiring layer 52.

In addition, in the embodiment and the like described above, descriptionhas been given of a case where the logic chip 10 and the sensor chip 20are electrically coupled to each other by the through electrodes 223 aand 223 b (FIG. 2); however, the logic chip 10 and the sensor chip 20may be electrically coupled to each other with use of another method.For example, the logic chip 10 and the sensor chip 20 may beelectrically coupled to each other with use of metal direct bonding suchas Cu—Cu bonding.

In addition, in the embodiment and the like described above, descriptionhas been given of an example in which the imaging device 1 includes asingle chip (the sensor chip 20) (FIG. 14) and an example in which theimaging device 1 includes two or three stacked chips (the logic chip 10,the sensor chip 20, and the memory chip 60) (FIGS. 2 and 15). Inaddition to the examples, the imaging device 1 may include four or morestacked chips.

It is to be noted that the effects described in the embodiment and thelike described above are merely exemplary, and may be any other effectsor may further include any other effects.

It is to be noted that the present disclosure may have the followingconfigurations.

(1)

An imaging device including:

a photoelectric converter;

a protection member provided on a light incidence side of thephotoelectric converter; a substrate opposed to the protection memberwith the photoelectric converter interposed therebetween and having afirst surface on the photoelectric converter side and a second surfaceopposed to the first surface;

a rewiring layer provided in a selective region of the second surface ofthe substrate; and

a protective resin layer provided on the second surface of thesubstrate,

the second surface of the substrate having an external terminal couplingregion exposed from the protective resin layer, and a stress relaxationregion exposed from the protective resin layer and disposed at aposition different from the external terminal coupling region.

(2)

The imaging device according to (1), further including an externalterminal provided on the second surface of the substrate, in which

in the external terminal coupling region, the external terminal isexposed from the protective resin layer.

(3)

The imaging device according to (2), in which the protective resin layeris provided to surround the external terminal.

(4)

The imaging device according to (3), in which, of the second surface ofthe substrate, a region other than a region in which the protectiveresin layer is provided to surround the external terminal includes theexternal terminal coupling region or the stress relaxation region.

(5)

The imaging device according to (1) or (2), in which the stressrelaxation region is provided at a position not overlapping the rewiringlayer.

(6)

The imaging device according to any one of (1) to (3), in which thesecond surface of the substrate further has a narrow pitch region inwhich the rewiring layers adjacent to each other are disposed at apredetermined interval, and a wide pitch region in which the rewiringlayers adjacent to each other are disposed at an interval larger thanthe interval in the narrow pitch region.

(7)

The imaging device according to (6), in which

the protective resin layer is provided in the narrow pitch region, and

the stress relaxation region is disposed at a position overlapping thewide pitch region.

(8)

The imaging device according to (7), in which

the protective resin layer is provided between the rewiring layersadjacent to each other in the narrow pitch region, and

the stress relaxation region is also disposed at a position overlappingthe rewiring layers in the narrow pitch region.

(9)

The imaging device according to any one of (1) to (8), furtherincluding:

a first chip provided with the photoelectric converter; and

a second chip including the substrate.

(10)

The imaging device according to (9), further including a third chipprovided between the first chip and the second chip.

(11)

The imaging device according to any one of (1) to (10), in which therewiring layer includes copper.

(12)

The imaging device according to any one of (1) to (11), in which thesubstrate includes a silicon substrate.

This application claims the benefit of Japanese Priority PatentApplication JP2018-114251 filed with Japan Patent Office on Jun. 15,2018, the entire contents of which are incorporated herein by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. An imaging device comprising: a photoelectricconverter; a protection member provided on a light incidence side of thephotoelectric converter; a substrate opposed to the protection memberwith the photoelectric converter interposed therebetween and having afirst surface on the photoelectric converter side and a second surfaceopposed to the first surface; a rewiring layer provided in a selectiveregion of the second surface of the substrate; and a protective resinlayer provided on the second surface of the substrate, the secondsurface of the substrate having an external terminal coupling regionexposed from the protective resin layer, and a stress relaxation regionexposed from the protective resin layer and disposed at a positiondifferent from the external terminal coupling region.
 2. The imagingdevice according to claim 1, further comprising an external terminalprovided on the second surface of the substrate, wherein in the externalterminal coupling region, the external terminal is exposed from theprotective resin layer.
 3. The imaging device according to claim 2,wherein the protective resin layer is provided to surround the externalterminal.
 4. The imaging device according to claim 3, wherein, of thesecond surface of the substrate, a region other than a region in whichthe protective resin layer is provided to surround the external terminalincludes the external terminal coupling region or the stress relaxationregion.
 5. The imaging device according to claim 1, wherein the stressrelaxation region is provided at a position not overlapping the rewiringlayer.
 6. The imaging device according to claim 1, wherein the secondsurface of the substrate further has a narrow pitch region in which therewiring layers adjacent to each other are disposed at a predeterminedinterval, and a wide pitch region in which the rewiring layers adjacentto each other are disposed at an interval larger than the interval inthe narrow pitch region.
 7. The imaging device according to claim 6,wherein the protective resin layer is provided in the narrow pitchregion, and the stress relaxation region is disposed at a positionoverlapping the wide pitch region.
 8. The imaging device according toclaim 7, wherein the protective resin layer is provided between therewiring layers adjacent to each other in the narrow pitch region, andthe stress relaxation region is also disposed at a position overlappingthe rewiring layers in the narrow pitch region.
 9. The imaging deviceaccording to claim 1, further comprising: a first chip provided with thephotoelectric converter; and a second chip including the substrate. 10.The imaging device according to claim 9, further comprising a third chipprovided between the first chip and the second chip.
 11. The imagingdevice according to claim 1, wherein the rewiring layer includes copper.12. The imaging device according to claim 1, wherein the substrateincludes a silicon substrate.